1. Field of the Invention
The present invention is concerned with mowers of the multiple rotor type. A series of side-by-side horizontally disposed discs rotating in opposite directions and having mowing blades associated therewith are adapted to cut hay and grasses and effect a windrowing of the cut hay and grasses between adjacent cooperative discs.
Although the blades from each of the rotors extend radially outwardly beyond the extent of the disc with which they are associated and into the field occupied by the adjacent disc there is no conflict of the mowing blades. In the past this possibility of blade conflict has been avoided by accurate "timing" of the disc drives. In the absence of such timing the conflict of blades was attempted to be rendered harmless by the yieldable mounting of such blades.
It is the present invention to provide for the transverse overlap of cutting of adjacent discs without blade conflict and without any drive timing. This is accomplished by vertically offsetting the blades of adjacent rotors --one set of blades being disposed beneath the disc and the blades of the adjacent disc or discs being disposed above the discs.
2. Description of the Prior Art
The prior United States mower patents to Zweegers U.S. Pat. Nos. 3,389,539; 3,391,522; and 3,443,369 and the United States patent to Van der Lely U.S. Pat. No. 3,550,360 all disclose the general feature of an aligned series of rotors extending transversely of the line of travel of the mowers. The rotors are provided with radially extending mowing blades which coact with each other to effect a cutting of hay and grasses. Each of these prior United States patents is and must be provided with a rotational drive for the rotors which are "timed" relative to each other to avoid blade contact.
My own prior U.S. Pat. No. 4,160,356 shows a similar type of mower and is particularly concerned with effecting rotational drive for the series of rotors. Attention is particularly directed to the "canting" of the rotors in FIG. 8 of the drawings of my earlier patent. The canting was employed to prevent blade contact between adjacent rotors without any special timing of the drive of those rotors.
In my presently pending application for United States patent, Ser. No. 140,617 I have utilized spring wire blades for association with mower rotors to make timing unnecessary. However, it has been found in practice that it is desirable to prevent any physical contact between the cooperative blades of mowers of this type. The present invention provides the mower cutting blades on the top side of one mower disc and on the bottom side of the adjacent mower discs. With all of the discs being horizontally aligned this means that although the mower can cut a full uninterrupted transverse swath there will be no blade interference because the cooperative blades are all vertically offset from one another.